|Publication number||US6515314 B1|
|Application number||US 09/713,394|
|Publication date||Feb 4, 2003|
|Filing date||Nov 16, 2000|
|Priority date||Nov 16, 2000|
|Also published as||US6777724, US20030094626|
|Publication number||09713394, 713394, US 6515314 B1, US 6515314B1, US-B1-6515314, US6515314 B1, US6515314B1|
|Inventors||Anil Raj Duggal, Alok Mani Srivastava, Steven Jude Duclos|
|Original Assignee||General Electric Company|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (10), Non-Patent Citations (3), Referenced by (217), Classifications (27), Legal Events (6)|
|External Links: USPTO, USPTO Assignment, Espacenet|
1. Field of the Invention
The present invention relates generally to lighting applications and, more particularly, to a light-emitting device having at least one organic luminescent layer doped with at least one photoluminescent material.
2. Description of the Related Art
Light-emitting diodes have gained increasing interest as sources for lighting. These devices are classified into inorganic light-emitting diodes (“LEDs”) and organic light-emitting devices (“OLEDs”). The technology for LEDs has progressed significantly, and typical semiconductor-based LEDs now can emit a range of colors in the green-to-red wavelengths. LEDs emitting blue or violet light are rare. Commercial blue LEDs are based on gallium nitride (GaN) or indium gallium nitride (InGaN). LEDs have been coated with phosphor particles to produce a mixture of the primary colors, resulting in white light. However, the manufacture of these devices is still complex and costly.
On the contrary, OLEDs offer the promise of low drive voltage requirement and simple manufacture. The simplest OLEDs typically consist of three layers deposited on a transparent substrate: an anode layer, an active layer of electroluminescent (“EL”) organic material, and a cathode layer. The EL organic material is either a low molecular weight organic material or a polymeric material having unsaturated bonds. Individual OLEDs typically emit broad-spectrum lights. To achieve a white light, prior-art devices incorporate closely arranged OLEDs emitting blue, green, and red light. These color lights are mixed to produce white light. An alternate scheme to produce white light is set forth in U.S. Pat. No. 5,294,870 which describes an organic EL multicolor display device comprising an organic EL source emitting blue light with green- and red-emitting fluorescent materials applied to different subpixel areas. This device emits different colors from the different subpixel areas by color shifting with the green- and red-emitting fluorescent materials. However, the manufacture of such microdevices is complex and requires sophisticated technologies.
Another example of an OLED is described in Junji Kido et al., “Multilayer White Light-Emitting Organic Electroluminescent Device,” 267 Science 1332-1334 (1995). This device includes three emitter layers with different carrier (or charge) transport properties, each emitting blue, green, or red light, which layers are used together to generate white light. However, the formation of successive layers requires a high degree of care so that the interfaces between the layers do not introduce unnecessary barriers to charge transport. In this device, the layers emitting the different colors typically degrade over time at different rates. Consequently, the color of light emitted from the device is likely to change over time. In addition, the uniformity of the light output over the emitting area of the device may be less than desirable because of imperfections at the interfaces between the layers.
Therefore, it is desirable to provide a light source based on organic EL materials that emits light at controllable wavelengths and is simple to manufacture. It is also desirable to use such light sources to produce white light.
A light-emitting device of the present invention comprises an anode, a cathode, and at least one organic EL material that is in contact with the anode and the cathode. The anode and the cathode are electrically isolated from one another. The organic EL material emits electromagnetic (“EM”) radiation having a first spectrum in response to an electrical voltage or an electrical field applied through the anode and the cathode. The electrical voltage or electrical field is applied by connecting the anode to a first electrical potential and connecting the cathode to a second electrical potential that is lower than the first. The organic EL material includes at least one photoluminescent (“PL”) material dispersed therein that absorbs a portion of the EM radiation emitted by the organic EL material and emits EM radiation having a second spectrum. When the EM radiation has the wavelength range in the visible spectrum (i.e, from about 380 nm to about 770 nm) the terms “light” and “EM radiation” are used interchangeably hereinafter. The organic EL material is formed into a thin film that is disposed between an anode and a cathode of the light-emitting device. The preferred PL materials comprise inorganic phosphors in the form of nanoparticles. The term “nanoparticles” as used in the present disclosure means particles having the largest dimension less than about 100 nm. The preferred largest dimension for the nanoparticles is less than about 50 nm. The inorganic phosphor nanoparticles are dispersed in the organic EL material prior to film formation. The PL material absorbs EM radiation having a shorter wavelength and emits EM radiation having a longer wavelength. In this case, the PL material is said to perform a down-conversion of the EM radiation. Other PL materials may be chosen to absorb EM radiation having a longer wavelength and emit EM radiation having a shorter wavelength. In this case, the PL material is said to perform an up-conversion of the EM radiation. Thus, the choice of the organic EL material and the PL material provides a control over the color of light emitted by the OLED.
Other features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments and the accompanying drawings in which the same numerals refer to like elements.
FIG. 1 is a schematic diagram of a three-layer organic light-emitting device of the present invention.
FIG. 2 shows the absorption and PL spectra of the yittrium aluminum oxide garnet phosphor doped with gadolinium and cerium.
FIG. 3 is a schematic diagram of a four-layer organic light-emitting device of the present invention.
FIG. 4 is a schematic diagram of a five-layer organic light-emitting device of the present invention.
FIG. 5 is a schematic diagram of another embodiment of a four-layer organic light-emitting device of the present invention.
FIG. 6 is a schematic diagram of the OLED of the present invention encapsulated in a protective shell.
FIG. 7 is a schematic diagram of a first embodiment of a flat panel display of the present invention.
FIG. 8 is a schematic diagram of a second embodiment of a flat panel display of the present invention.
FIG. 9 is a schematic diagram of an arrangement of the OLEDs to form a white light source.
There has been an increasing need to have thin, flat, inexpensive, extended white light sources with a high color rendition index (“CRI”) and a color temperature in the range of 3000-6500° K for general illumination applications. In addition, the demand for flat panel displays having full color and high resolution also increases significantly with the explosive growth of television, computer terminals, and portable electronic devices.
The present invention provides a light-emitting device that can emit light having a color temperature in the range of about 1000° K to over 10000° K, corresponding to red to blue color. A particular color temperature is achieved by the choice of the particular organic EL material and the phosphor materials.
According to another embodiment of the present invention, a plurality of the light-emitting devices of the present invention is incorporated in a substantially flat panel display or a large lighting device for illumination of an area.
The color temperature of a light source refers to the temperature of a blackbody source having the closest color match to the light source in question. The color match is typically represented and compared on a conventional CIE (Commission International de I'Eclairage) chromaticity diagram. See, for example, “Encyclopedia of Physical Science and Technology,” Vol. 7, 230-231 (Robert A. Meyers (Ed.), 1987). Generally, as the color temperature increases, the light becomes bluer. As the color temperature decreases, the light appears redder.
The CRI is a measure of the degree of distortion in the apparent colors of a set of standard pigments when measured with the light source in question as opposed to a standard light source. The CRI can be determined by calculating the color shift; e.g., quantified as tristimulus values, produced by the light source in question as opposed to the standard light source. Typically, for color temperatures below 5000° K, the standard light source used is a blackbody of the appropriate temperature. For color temperatures greater than 5000° K, sunlight is typically used as the standard light source. Light sources having a relatively continuous output spectrum, such as incandescent lamps; typically have a high CRI, e.g. equal to or near 100. Light sources having a multi-line output spectrum, such as high pressure discharge lamps, typically have a CRI ranging from about 50 to 80. Fluorescent lamps typically have a CRI greater than about 60.
According to one embodiment of the present invention, the organic EL material emits EM radiation having a wavelength in the range from UV to blue light (i.e., from about 300 nm to about 500 nm) in response to an applied voltage or an applied electrical field, and the inorganic phosphors absorb EM radiation having a wavelength in the range of ultraviolet to blue light and emit light having a wavelength in the range of blue to red light (i.e., from about 400 nm to about 770 nm). The source for the applied voltage may be a direct current (“DC”) source or an alternating current (“AC”) source.
The organic EL film or layer of the present invention is typically disposed between an anode layer and a cathode layer of the light-emitting device. The multilayer assemblage of anode, organic EL film, and cathode is typically supported on a substantially transparent substrate, such as glass, quartz, or a substantially transparent polymeric material. The substrate allows at least 80%, preferably at least 95%, more preferably at least 99%, and most preferably at least 99.9%, light transmitted therethrough. Examples of polymeric materials suitable for use as the substrate are polycarbonate, silicone, polyacrylate, polyethylene terephthalate, and epoxy resins. One or more additional layers of other organic or metallic materials may be included between the anode and the cathode to increase the efficiency for injecting charges into or for carrying those charges to the active organic EL film. When an additional metallic film is used to facilitate the transport positive charges or holes to the active organic EL layer, their thickness is kept to a minimum, preferably less than 50 nm, so that light emitted from the organic layer can escape substantially unalterably. The thickness of any additional layer used to facilitate the transport of electrons to the active organic EL layer, on the other hand, may be larger as long as it is not excessive such that the layer presents an excessive barrier to the injection of electrons.
Exemplary embodiments of the present invention provide advantages over known devices. For example, the light emitted from the organic light emitting device is scattered because of the presence of the nanoparticles, and the light scattering provides improved uniformity in light output over the area of the light source. Also, because most phosphors are relatively stable over time, a light source according to exemplary embodiments of the invention has good color stability over time.
As examples of embodiments of the invention, the light source comprises an OLED that emits light in the blue or ultraviolet (“UV”) spectral region (i.e., wavelengths in the range of about 300 nm to about 500 nm). FIG. 1 is a schematic diagram of the first preferred embodiment of the light-emitting device of the present invention. The OLED 10 comprises three layers: an anode layer 30, a layer of organic EL material 40, and a cathode layer 50. The assemblage of the layers is disposed on a substantially transparent substrate 20 such as glass, quartz, or a substantially transparent polymer. The substrate allows at least 80%, preferably at least 95%, more preferably at least 99%, and most preferably 99.9%, light transmitted therethrough. The polymer may be formed into a rigid or a flexible flat piece made of a polycarbonate, silicone, polyacrylate, polyethylene terephthalate, epoxy resin, or the like. However, in certain circumstances, it may be desirable to form the OLED on a curved substrate.
The anode layer 30 injects positive charge carriers (or holes) into the organic EL layer when an electrical voltage is applied across the OLED 10. The anode layer is preferably made of a metal having a high work function; e.g., greater than about 4.5 eV, preferably from about 4.5 eV to about 5.5 eV. Indium tin oxide (“ITO”) is typically used for this purpose. The thickness of the ITO anode layer is typically in the range from about 50 nm to 400 nm, preferably from about 50 nm to about 200 nm. ITO is substantially transparent to light transmission and allows at least 80% light transmitted therethrough. Therefore, light emitted from the organic EL layer 40 can easily escape through the ITO anode without being seriously attenuated. Other materials suitable for use as the anode layer are tin oxide, indium oxide, zinc oxide, indium zinc oxide, and mixtures thereof.
The cathode layer 50 injects negative charge carriers (electrons) into the organic EL layer 40 when a voltage is applied across the OLED 10 and is selected from a material having a low work function; e.g, less than about 4 eV. Materials suitable for use as a cathode are K, Li, Na, Mg, La, Ce, Ca, Sr, Ba, Al, Ag, In, Sn, Zn, Zr, or mixtures thereof. Preferred materials for the manufacture of cathodes are Ag—Mg, Al—Li, In—Mg, and Al—Ca alloys. The thickness of the cathode layer is preferably kept in the range from about 50 nm to about 500 nm, preferably from about 50 nm to about 200 nm.
The organic EL layer 40 serves as the transport medium for both holes and electrons. In this layer these excited species combine and drop to a lower energy level, concurrently emitting EM radiation in the visible range. The preferred organic EL materials are those capable of electroluminescing in the range of UV to blue light. More preferably, the organic materials electroluminesce in the wavelength range from about 300 nm to about 450 nm. The thickness of the organic EL layer 40 is preferably kept in the range of about 100 to about 300 nm. The organic EL material may be a polymer, a copolymer, a mixture of polymers, or lower molecular-weight organic molecules having unsaturated bonds. Such materials possess a delocalized π-electron system, which gives the polymer chains or organic molecules the ability to support positive and negative charge carriers with high mobility. Suitable EL polymers are poly(N-vinylcarbazole) (“PVK”, emitting violet-to-blue light in the wavelengths of about 380-500 nm); poly(alkylfluorene) such as poly(9,9-dihexylfluorene) (410-550 nm), poly(dioctylfluorene) (wavelength at peak EL emission of 436 nm), or poly[9,9-bis(3,6-dioxaheptyl)-fluorene-2,7-diyl] (400-550 nm); poly(praraphenylene) derivatives such as poly(2-decyloxy-1,4-phenylene) (400-550 nm). Mixtures of these polymers or copolymers based on one or more of these polymers and others may be used as long as the resulting polymeric material preferably emits blue light. For example, a copolymer of 2,7-dibromo-9,9-di-n-hexylfluorene and 9,10-dibromoanthracene emits light in the wavelength range of 400-525 nm.
Another class of suitable EL polymers is the polysilanes. Polysilanes are linear silicon-backbone polymers substituted with a variety of alkyl and/or aryl side groups. They are quasi one-dimensional materials with delocalized σ-conjugated electrons along polymer backbone chains. Examples of polysilanes are poly(di-n-butylsilane), poly(di-n-pentylsilane), poly(di-n-hexylsilane), poly(methylphenylsilane), and poly[bis(p-butylphenyl)silane] which are disclosed in H. Suzuki et al., “Near-Ultraviolet Electroluminescence From Polysilanes,” 331 Thin Solid Films 64-70 (1998). These polysilanes emit light having wavelengths in the range from about 320 nm to about 420 nm.
Organic materials having molecular weight less than about 5000 that are made of a large number of aromatic units are also applicable. An example of such materials is 1,3,5-tris[N-(4-diphenylaminophenyl) phenylamino] benzene, which emits light in the wavelength range of 380-500 nm. The organic EL layer also may be prepared from lower molecular weight organic molecules, such as phenylanthracene, tetraarylethene, coumarin, rubrene, tetraphenylbutadiene, anthracene, perylene, coronene, or their derivatives. These materials generally emit light having maximum wavelength of about 520 nm. Still other suitable materials are the low molecular-weight metal organic complexes such as aluminum-, gallium-, and indium-acetylacetonate, which emit light in the wavelength range of 415-457 nm, aluminum-(picolymethylketone)-bis[2,6-di(t-butyl)phenoxide] or scandium-(4-methoxy-picolylmethylketone)-bis(acetylacetonate), which emits in the range of 420-433 nm. The preferred organic EL materials are those emit light predominantly below 450 nm such as PVK or polysilanes.
At least one phosphor material is dispersed uniformly in the organic EL layer. The phosphor material is preferably of an inorganic type and is in the form of nanoparticles. The nanoparticles have a particle size distribution such that more than 95 percent of the particles have the largest dimension less than 100 nm, preferably less than 50 nm, and most preferably less than 30 nm. The smaller particle size is preferred because the particles will disperse well in the organic medium and the resulting organic EL layer would have a smoother surface. The phosphor nanoparticles may be prepared from larger pieces of phosphor material by any grinding or pulverization method, such as ball milling using zirconia-toughened balls or jet milling. They also may be prepared by crystal growth from solution, and their size may be controlled by terminating the crystal growth at an appropriate time. The preferred phosphor materials efficiently absorb EM radiation emitted by the organic EL material in the ultraviolet-to-blue spectral region (i.e., wavelengths in the range from 100 nm to about 480 nm, preferably from about 350 nm to about 450 nm) and re-emit light in the blue-to-red spectral region (i.e., wavelength in the range from about 450 nm to about 770 nm). A particular phosphor material may be chosen to emit a desired color. A mixture of phosphors such as those emitting blue, green, and red light may be used if a white light is desired. An exemplary phosphor is the cerium-doped yttrium aluminum oxide Y3Al5O12 garnet (“YAG”). Other suitable phosphors are based on YAG doped with more than one type of rare earth ions, such as (Y1−x−yGdxCey)3Al5O12 (“YAG:Gd,Ce”), (Y1−xCex)3(Al1−yGay)O12 (“YAG:Ga,Ce”), (Y1−x−yGdxCey)(Al5−Gaz)O12 (“YAG:Gd,Ga,Ce”), and (Gd1−xCex)Sc2Al3O12 (“GSAG”) where 0≦x≦1, 0≦y≦1, 0≦z≦5 and x+y≦1. For example, FIG. 2 shows the emission PL spectrum of the YAG:Gd,Ce phosphor. This material shows an absorption of light in the wavelength range from about 390 nm to about 530 nm (i.e., the blue spectral region) and an emission of light in the wavelength range from about 490 nm to about 700 nm (i.e., the green-to-red spectral region). The following are examples of phosphors that are efficiently excited by EM radiation emitted in the wavelength region of 300 nm to about 500 nm by polysilanes and their derivatives.
Green-emitting phosphors: Ca8Mg(SiO4)4Cl2:Eu2+,Mn2+; GdBO3:Ce3+,Tb3+; CeMgAl11O19: Tb3+; Y2SiO5:Ce3+,Tb3+; and BaMg2Al16O27:Eu2+,Mn2+;
Red-emitting phosphors: Y2O3:Bi3+,Eu3+; Sr2P2O7:Eu2+,Mn2+; SrMgP2O7:Eu2+,Mn2+; (Y,Gd)(V,B)O4:Eu3+; and 3.5MgO.0.5MgF2.GeO2:Mn4+;
Blue-emitting phosphors: BaMg2Al16O27:Eu2+ and Sr5(PO4)10Cl2:Eu2+
Still other ions may be incorporated into the phosphor to transfer energy from the light emitted from the organic material to other activator ions in the phosphor host lattice as a way to increase the energy utilization. For example, when Sb3+ and Mn2+ ions exist in the same phosphor lattice, Sb3+ efficiently absorbs light in the blue region, which is not absorbed very efficiently by Mn2+, and transfers the energy to Mn2+ ion. Thus, a larger total amount of light emitted by the organic EL material is absorbed by both ions, resulting in higher quantum efficiency of the total device.
The phosphor nanoparticles are dispersed in the organic EL film-forming material. A phosphor composition of less than about 30, preferably less than about 10, percent by volume of the mixture of organic material and phosphor is used. A solvent may be added into the mixture to adjust the viscosity of the organic material to a desired level. The mixture of the organic EL material and phosphor nanoparticles is applied by conventional techniques such as spin coating, spray coating, dip coating, roller coating, or ink-jet printing on the anode thin film that has been formed on the substantially transparent substrate. Spin coating is the preferred method when the mixture does not have very high viscosity. However, when it is desired to form the organic EL material on many small areas, the ink-jet printing method may be preferred.
In addition to the anode, organic EL, and the cathode layers, one or more additional layers may be included to increase the efficiency of the overall device. For example, these additional layers can serve to improve the injection (electron or hole injection enhancement layers) or transport (electron or hole transport layers) of charges into the organic EL layer. The thickness of each of these layers is kept to below 500 nm, preferably below 100 nm. Materials for these additional layers are typically low-to-intermediate molecular weight (less than about 2000) organic molecules. They may be applied during the manufacture of the OLED by conventional methods such as spin coating, spray coating, dip coating, roller coating, ink-jet-printing, or physical or chemical vapor deposition. In another embodiment of the present invention, as shown schematically in FIG. 3, a hole injection enhancement layer 32 is formed between the anode layer 30 and the organic EL layer 40 to provide a higher injected current at a given forward bias and/or a higher maximum current before the failure of the device. Thus, the hole injection enhancement layer facilitates the injection of holes from the anode. Suitable materials for the hole injection enhancement layer are arylene-based compounds disclosed in U.S. Pat. No. 5,998,803; such as 3,4,9,10-perylenetetra-carboxylic dianhydride or bis(1,2,5-thiadiazolo)-p-quinobis(1,3-dithiole).
In another embodiment of the present invention, as shown schematically in FIG. 4, the OLED 10 further includes a hole transport layer 34 which is disposed between the hole injection enhancement layer 32 and the organic EL layer 40. The hole transport layer 34 has the functions of transporting holes and blocking the transportation of electrons so that holes and electrons are optimally combined in the organic EL layer. Materials suitable for the hole transport layer are triaryldiamine, tetraphenyldiamine, aromatic tertiary amines, hydrazone derivatives, carbazole derivatives, triazole derivatives, imidazole derivatives, oxadiazole derivatives having an amino group, and polythiophenes as disclosed in U.S. Pat. No. 6,023,371.
In still another embodiment of the present invention, as shown schematically in FIG. 5, the OLED 10 includes an additional layer 42 which is disposed between the cathode layer 50 and the organic EL layer 40. Layer 42 has the combined function of injecting and transporting electrons to the organic EL layer. Materials suitable for the electron injecting and transporting layer are metal organic complexes such as tris(8-quinolinolato)aluminum, oxadiazole derivatives, perylene derivatives, pyridine derivatives, pyrimidine derivatives, quinoline derivatives, quinoxaline derivatives, diphenylquinone derivatives, and nitro-substituted fluorene derivatives, as disclosed in U.S. Pat. No. 6,023,371.
When one or more additional layers other than the organic EL layer are included in the OLED, such as for hole injection enhancement, hole transport, electron injection enhancement and transport, nanoparticles of one or more phosphors disclosed above may be dispersed therein. An exemplary purpose for such an inclusion of phosphor nanoparticles is to further tune the color of the light emitted from the OLED.
In still another embodiment of the present invention, as shown schematically in FIG. 6, the complete OLED 10 may be encapsulated in a substantially transparent and thin shell 60 of a polymeric material to retard the negative impact of oxygen and/or moisture on the useful life of the OLED 10. This shell may be formed by any conventional technique such as spray coating, dip coating, or chemical vapor deposition, followed by curing. The shell preferably has a thickness less than about 100 nm after curing. Although the OLED 10 shown in FIG. 6 includes only the substrate, the anode, the organic EL layer, and the cathode, it should be appreciated that any or all of the hole injection enhancement layer, the hole transport layer, and the electron injection enhancement and transport layer also may be included before the formation of the protective shell 60.
One or more OLEDs of the present invention may be included in a light-emitting flat panel display. The completed OLEDs may be attached to a common substrate or the layers of the individual OLEDs may be formed directly on defined areas of the common substrate. Each OLED or group of OLEDs may be provided with its own electrical power source, and the energization of different OLEDs or groups of OLEDs with respect to the schedule or level of the power applied may be controlled by a controller. An example is shown in FIG. 7. A flat panel color display 100 comprises a substantially transparent substrate 120 on which a thin anode layer 130 is formed. This anode layer is typically made of transparent ITO. In a preferred embodiment, a plurality of pixels (e.g., 140-143) of organic EL materials, each having one or more types of phosphor nanoparticles dispersed therein, is deposited on the anode layer at distinct positions. The organic EL materials are preferably applied by the ink-jet printing method. This technique provides an inexpensive method of depositing the organic EL materials in very fine pixels.
Alternatively, larger objects or figures may be formed, for example, by spray coating or printing. The thickness of each individual EL pixel, object, or figure may vary to provide the optimum brightness and appearance of the display. The pixels, objects, or FIGS. may be deposited adjacently to one another to form a continuous layer. It may be desirable, in certain circumstances, to provide a partition between two adjacent pixels, objects, or figures. In this case, the partition is desirably made of an organic EL material that is different from the organic EL materials of the adjacent pixels, objects, or figures. In other circumstances, the partition may be desirably made of an organic material that is not electroluminescent. More than one layer of phosphor-dispersed organic EL material may be formed one on top of another to achieve the object of the display. A common cathode layer 150 is deposited on the exposed surface of the organic EL layer. In this case a common electrical power supplied is provided to the display. Alternatively, a separate cathode pixel or region may be deposited on each separate organic EL pixel or region as denoted by numerals 150-153 in FIG. 8. A convenient method of applying the separate cathode pixels or regions is by employing successive masks with the desired patterns. When one mask is applied, the cathode pixels are formed at the openings in the mask. Another mask is subsequently applied to form cathode pixels on other organic EL pixels. When separate cathode pixels or regions are formed, insulating partitions are preferably provided between them, and a separate power supply may be provided to each individual OLED which comprises the anode, the individual organic EL pixel or region, and the corresponding cathode pixel or region directly adjacent to it. In addition, additional layers for hole injection enhancement, hole transport, and electron injection enhancement and transport may be include as disclosed above. The various preferred materials disclosed in the foregoing are equally applicable to the manufacture of the flat panel display.
In another embodiment of the present invention, a white-light source is produced by integrating a plurality of light-emitting devices, each emitting one of blue, green, or red color. The individual OLEDs are arranged adjacently on a substantially transparent substrate such that two adjacent OLEDs emit two different colors. Preferably, the OLEDs are arranged in a matrix of rows and columns such that the OLEDs of each row or column form a periodic light color pattern; e.g, blue-green-red. In this way, the lights emitted by adjacent OLEDs are mixed to produce a white light.
Methods of producing OLEDs, panel displays, and large-area light sources of the present invention are now described.
A substantially transparent substrate piece such as glass is provided. The substrate piece may be previously cleaned with a compatible liquid, such as a dilute acid solution, and dried in a clean environment. An anode material, such as ITO, is sputter-deposited on the substrate piece to form an anode layer. The, anode layer may be patterned further by etching. Preferably, the anode pattern is provided with an area from which a connection to an electrical voltage source may be made. The organic EL material is mixed with a desired amount of nanoparticles of at least one chosen PL material to produce a well-dispersed mixture. A quantity of a compatible solvent may be added to the mixture to adjust its viscosity to a desired level for ease of application on the anode. The solvent is preferably an organic solvent having high a vapor pressure such that it can be easily removed from the organic EL layer after it has been formed. Suitable solvents are acetone, low molecular weight alcohols, cyclohexane, toluene, or xylene. When the desired EL material is a polymeric material, monomers or oligomers of the polymeric material may be used in the mixture and a further polymerization of the monomers or oligomers may be carried out after the film has been formed. The mixture is deposited on the anode by any conventional method such as spin coating, spray coating, dip coating, roller coating, or ink-jet printing. Spin coating and ink-jet printing are preferred. The partially formed device at this stage may be dried at a low temperature, preferably under a sub-atmospheric pressure. The organic EL material may require a polymerization by an appropriate initiation. For example, EM radiation having an appropriate wavelength, such as in the UV range, or heat may complete the polymerization process. In other instances, a soluble polymerization catalyst may be provided in the mixture before the film is formed. In still other instances, the catalyst may be applied on the organic EL layer to initiate the polymerization, for example, by spraying. When a catalyst is used for the polymerization, it may be removed and the partially completed device may be dried in a clean environment. The cathode layer is next formed by sputter-depositing the cathode material, from one or more sources, on the organic EL layer. An electrical lead is attached to the cathode layer for a connection to the lower electrical potential of the voltage source. The device may be further encapsulated in a thin shell of a substantially transparent polymer. The shell may be formed by dip coating and curing the polymer. When additional layers of hole injection enhancement and transport material or electron injection enhancement and transport material are included in the OLED, they may be applied on the appropriate previously-formed layer by spin coating, spray coating, dip coating, roller coating, or ink-jet printing. The preferred method is ink-jet printing.
A plurality of the OLEDs thus made may be integrated together on a large-area transparent substrate to form a panel display or a light source for general lighting purposes. The individual OLEDs are attached to the substrate in a desired pattern with a thin layer of adhesive, such as a thermoplastic material or an epoxy resin. To produce a large-area white light source, a plurality of OLEDs 10 are preferably attached on the substrate 20 with a layer of adhesive in a matrix of rows and columns. The OLEDs are arranged such that two adjacent OLEDs 10 emit two different light colors selected from blue (“B”), green (“G”), and red (“R”); and the OLEDs 10 form a periodic pattern of colors, such as blue-green-red. FIG. 9 shows an example of such an arrangement. Alternatively, one single anode layer may be deposited on the substrate. Then the individual organic EL materials having nanoparticles dispersed therein are deposited on the anode layer in the desired pattern by ink-jet printing. Partitions of a non-conductive organic material are the deposited between the EL materials by, for example, ink-jet printing or chemical vapor deposition through an applied mask. Individual cathodes are then deposited on each individual organic EL material with non-conductive partitions provided between them. The cathodes in this case may be deposited by the conventional photolithography method.
While specific preferred embodiments of the present invention have been described in the foregoing, it will be appreciated by those skilled in the art that many modifications, substitutions, or variations may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US4769292 *||Oct 14, 1987||Sep 6, 1988||Eastman Kodak Company||Electroluminescent device with modified thin film luminescent zone|
|US5126214 *||Mar 5, 1990||Jun 30, 1992||Idemitsu Kosan Co., Ltd.||Electroluminescent element|
|US5294870||Dec 30, 1991||Mar 15, 1994||Eastman Kodak Company||Organic electroluminescent multicolor image display device|
|US5683823 *||Jan 26, 1996||Nov 4, 1997||Eastman Kodak Company||White light-emitting organic electroluminescent devices|
|US5717289 *||Jan 29, 1997||Feb 10, 1998||Nec Corporation||Thin film electroluminescent element easily regulating emitted light to white|
|US5813753 *||May 27, 1997||Sep 29, 1998||Philips Electronics North America Corporation||UV/blue led-phosphor device with efficient conversion of UV/blues light to visible light|
|US5943354 *||Sep 16, 1997||Aug 24, 1999||Brown University Research Foundation||Optical sources having a strongly scattering gain medium providing laser-like action|
|US5998803||May 29, 1997||Dec 7, 1999||The Trustees Of Princeton University||Organic light emitting device containing a hole injection enhancement layer|
|US6023371||Jun 8, 1998||Feb 8, 2000||Tdk Corporation||Color conversion material, and organic electroluminescent color display using the same|
|US6252254 *||Nov 30, 1998||Jun 26, 2001||General Electric Company||Light emitting device with phosphor composition|
|1||"Encyclopedia of Physical Science and Technology," vol. 7, 230-231 (Robert A Meyers (Ed.), 1987).|
|2||H. Suzuki et al., "Near-Ultraviolet Electroluminescence From Polysilanes," 331 Thin Solid Films 64-70 (1998).|
|3||Junji Kido et al., "Multilayer White Light-Emitting Organic Electroluminescent Device," 267 Science 1332-1334 (1995).|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US6710366||Aug 2, 2002||Mar 23, 2004||Ultradots, Inc.||Nanocomposite materials with engineered properties|
|US6734465 *||Nov 19, 2002||May 11, 2004||Nanocrystals Technology Lp||Nanocrystalline based phosphors and photonic structures for solid state lighting|
|US6787990 *||May 28, 2002||Sep 7, 2004||Eastman Kodak Company||OLED area illumination light source having flexible substrate on a support|
|US6794265||Aug 2, 2002||Sep 21, 2004||Ultradots, Inc.||Methods of forming quantum dots of Group IV semiconductor materials|
|US6803607||Jun 13, 2003||Oct 12, 2004||Cotco Holdings Limited||Surface mountable light emitting device|
|US6819845||Aug 2, 2002||Nov 16, 2004||Ultradots, Inc.||Optical devices with engineered nonlinear nanocomposite materials|
|US6846565||Mar 28, 2002||Jan 25, 2005||Board Of Regents, The University Of Texas System||Light-emitting nanoparticles and method of making same|
|US6853132 *||Feb 19, 2002||Feb 8, 2005||Seiko Epson Corporation||EL element, EL display, and electronic apparatus|
|US6903505 *||Dec 17, 2001||Jun 7, 2005||General Electric Company||Light-emitting device with organic electroluminescent material and photoluminescent materials|
|US6918946 *||Mar 28, 2002||Jul 19, 2005||Board Of Regents, The University Of Texas System||Applications of light-emitting nanoparticles|
|US6961499||Jul 16, 2004||Nov 1, 2005||Ultradots, Inc.||Optical devices with engineered nonlinear nanocomposite materials|
|US6970490 *||May 10, 2002||Nov 29, 2005||The Trustees Of Princeton University||Organic light emitting devices based on the formation of an electron-hole plasma|
|US6995505 *||Oct 31, 2003||Feb 7, 2006||Korea Institute Of Science And Technology||Polymeric electroluminescent device using an emitting layer of nanocomposites|
|US7005197 *||Feb 14, 2002||Feb 28, 2006||Hitachi, Ltd.||Light source and display using the same|
|US7026755||Aug 7, 2003||Apr 11, 2006||General Electric Company||Deep red phosphor for general illumination applications|
|US7088038||Jul 2, 2003||Aug 8, 2006||Gelcore Llc||Green phosphor for general illumination applications|
|US7221093 *||Jun 10, 2002||May 22, 2007||Institute Of Materials Research And Engineering||Patterning of electrodes in OLED devices|
|US7241399 *||Sep 7, 2001||Jul 10, 2007||Centrum Fuer Angewandte Nanotechnologie (Can) Gmbh||Synthesis of nanoparticles|
|US7259443 *||Jun 25, 2004||Aug 21, 2007||E.I. Du Pont De Nemours And Company||Methods for forming patterns on a filled dielectric material on substrates|
|US7274045||Mar 17, 2005||Sep 25, 2007||Lumination Llc||Borate phosphor materials for use in lighting applications|
|US7279832||Apr 1, 2004||Oct 9, 2007||Innovalight, Inc.||Phosphor materials and illumination devices made therefrom|
|US7358542||Feb 2, 2005||Apr 15, 2008||Lumination Llc||Red emitting phosphor materials for use in LED and LCD applications|
|US7459338 *||Mar 11, 2005||Dec 2, 2008||Canon Kabushiki Kaisha||Substrate, conductive substrate, fine structure substrate, organic field effect transistor and manufacturing method thereof|
|US7497973||Feb 28, 2006||Mar 3, 2009||Lumination Llc||Red line emitting phosphor materials for use in LED applications|
|US7541097||Feb 18, 2004||Jun 2, 2009||Lg Display Co., Ltd.||Organic electroluminescent device and method for fabricating the same|
|US7550919||Mar 26, 2004||Jun 23, 2009||Sanyo Electric Co., Ltd.||Organic electroluminescent device with reduced initial drive voltage and manufacturing method thereof|
|US7608829||Oct 27, 2009||General Electric Company||Polymeric composite scintillators and method for making same|
|US7615920 *||Sep 19, 2006||Nov 10, 2009||Samsung Electronics Co., Ltd.||Light emitting device and display apparatus using the same|
|US7625502||Dec 1, 2009||General Electric Company||Nano-scale metal halide scintillation materials and methods for making same|
|US7648649||Feb 13, 2007||Jan 19, 2010||Lumination Llc||Red line emitting phosphors for use in led applications|
|US7663300 *||Feb 16, 2010||Universal Display Corporation||Organic light emitting devices for illumination|
|US7670581||Mar 2, 2010||Brian A. Korgel||Light-emitting nanoparticles and methods of making same|
|US7708968||Mar 26, 2007||May 4, 2010||General Electric Company||Nano-scale metal oxide, oxyhalide and oxysulfide scintillation materials and methods for making same|
|US7718707 *||Aug 21, 2007||May 18, 2010||Innovalight, Inc.||Method for preparing nanoparticle thin films|
|US7750352 *||Aug 10, 2005||Jul 6, 2010||Pinion Technologies, Inc.||Light strips for lighting and backlighting applications|
|US7819910||May 25, 2004||Oct 26, 2010||Ledeep Llc||Skin tanning and light therapy system|
|US7847309||Jul 16, 2008||Dec 7, 2010||GE Lighting Solutions, LLC||Red line emitting complex fluoride phosphors activated with Mn4+|
|US7888857 *||Feb 15, 2011||Samsung Electronics Co., Ltd.||Light emitting device with three-dimensional structure and fabrication method thereof|
|US7921853||Mar 9, 2005||Apr 12, 2011||Ledeep Llc||Phototherapy method for treating psoriasis|
|US7959827||Jun 14, 2011||General Electric Company||Persistent phosphor|
|US7982214 *||Dec 7, 2007||Jul 19, 2011||Koninklijke Philips Electronics N.V.||Voltage-operated layered arrangement|
|US7982390 *||Jul 1, 2004||Jul 19, 2011||Panasonic Corporation||Light emitting element and display device having an inorganic phosphor layer|
|US8062553||Nov 22, 2011||E. I. Du Pont De Nemours And Company||Compositions of polyaniline made with perfuoropolymeric acid which are heat-enhanced and electronic devices made therewith|
|US8100734||Jan 24, 2012||Universal Display Corporation||Organic light emitting devices for illumination|
|US8128249||Aug 28, 2007||Mar 6, 2012||Qd Vision, Inc.||Apparatus for selectively backlighting a material|
|US8153029||Dec 20, 2007||Apr 10, 2012||E.I. Du Pont De Nemours And Company||Laser (230NM) ablatable compositions of electrically conducting polymers made with a perfluoropolymeric acid applications thereof|
|US8215787||Jul 10, 2012||Plextronics, Inc.||Organic light emitting diode products|
|US8222807||Feb 15, 2008||Jul 17, 2012||Mitsubishi Chemical Corporation||Organic electroluminescence device and method of producing organic device|
|US8241526||Aug 14, 2012||E I Du Pont De Nemours And Company||Aqueous dispersions of electrically conducting polymers containing high boiling solvent and additives|
|US8288951||Oct 16, 2012||Plextronics, Inc.||Organic light emitting diode lighting systems|
|US8318046||Nov 27, 2012||E I Du Pont De Nemours And Company||Water dispersible polyanilines made with polymeric acid colloids for electronics applications|
|US8333907||Dec 18, 2012||Utc Fire & Security Corporation||Articles using persistent phosphors|
|US8338512||Dec 25, 2012||E I Du Pont De Nemours And Company||Electrically conducting organic polymer/nanoparticle composites and method for use thereof|
|US8405063||Mar 26, 2013||Qd Vision, Inc.||Quantum dot light enhancement substrate and lighting device including same|
|US8409476||Apr 2, 2013||E I Du Pont De Nemours And Company||High work function transparent conductors|
|US8414304||Apr 9, 2013||Plextronics, Inc.||Organic light emitting diode lighting devices|
|US8455865||Jun 4, 2013||E I Du Pont De Nemours And Company||Electrically conducting organic polymer/nanoparticle composites and methods for use thereof|
|US8471170||May 1, 2008||Jun 25, 2013||Innovalight, Inc.||Methods and apparatus for the production of group IV nanoparticles in a flow-through plasma reactor|
|US8491819||Mar 25, 2011||Jul 23, 2013||E I Du Pont De Nemours And Company||High work-function and high conductivity compositions of electrically conducting polymers|
|US8519424||Aug 18, 2009||Aug 27, 2013||Plextronics, Inc.||User configurable mosaic light emitting apparatus|
|US8545723||Mar 30, 2011||Oct 1, 2013||General Electric Company||Persistent phosphor|
|US8585931||Jul 29, 2008||Nov 19, 2013||E I Du Pont De Nemours And Company||Water dispersible polythiophenes made with polymeric acid colloids|
|US8618595||May 5, 2005||Dec 31, 2013||Merck Patent Gmbh||Applications of light-emitting nanoparticles|
|US8641926||May 13, 2008||Feb 4, 2014||E I Du Pont De Nemours And Company||Water dispersible polythiophenes made with polymeric acid colloids|
|US8642977||Sep 5, 2008||Feb 4, 2014||Qd Vision, Inc.||Article including semiconductor nanocrystals|
|US8692242 *||Dec 24, 2012||Apr 8, 2014||National Tsing Hua University||Candlelight-like light organic light-emitting device|
|US8718437||Sep 12, 2008||May 6, 2014||Qd Vision, Inc.||Compositions, optical component, system including an optical component, devices, and other products|
|US8747697 *||Jun 7, 2011||Jun 10, 2014||Cree, Inc.||Gallium-substituted yttrium aluminum garnet phosphor and light emitting devices including the same|
|US8759850||Mar 25, 2013||Jun 24, 2014||Qd Vision, Inc.||Quantum dot light enhancement substrate|
|US8765022||Jan 16, 2013||Jul 1, 2014||E I Du Pont De Nemours And Company||Water dispersible polypyrroles made with polymeric acid colloids for electronics applications|
|US8784692||Mar 6, 2013||Jul 22, 2014||E I Du Pont De Nemours And Company||Water dispersible polythiophenes made with polymeric acid colloids|
|US8836212||Jan 11, 2007||Sep 16, 2014||Qd Vision, Inc.||Light emissive printed article printed with quantum dot ink|
|US8836221||Sep 19, 2012||Sep 16, 2014||Solvay Usa, Inc.||Organic light emitting diode lighting systems|
|US8845933||Apr 21, 2010||Sep 30, 2014||E I Du Pont De Nemours And Company||Electrically conductive polymer compositions and films made therefrom|
|US8876272||Dec 22, 2009||Nov 4, 2014||Qd Vision, Inc.||Compositions and methods including depositing nanomaterial|
|US8945426||Mar 12, 2010||Feb 3, 2015||E I Du Pont De Nemours And Company||Electrically conductive polymer compositions for coating applications|
|US8945427||Apr 23, 2010||Feb 3, 2015||E I Du Pont De Nemours And Company||Electrically conductive polymer compositions and films made therefrom|
|US8951443||Apr 27, 2011||Feb 10, 2015||Novaled Ag||Organic semiconducting material and electronic component|
|US8968438||Apr 15, 2009||Mar 3, 2015||Innovalight, Inc.||Methods and apparatus for the in situ collection of nucleated particles|
|US9006753||Mar 12, 2009||Apr 14, 2015||Qd Vision, Inc.||Electroluminescent display useful for displaying a predetermined pattern|
|US9054329||Nov 24, 2008||Jun 9, 2015||Qd Vision, Inc.||Light-emitting devices and displays with improved performance|
|US9120149||Dec 19, 2008||Sep 1, 2015||Qd Vision, Inc.||Methods and articles including nanomaterial|
|US9155157||Aug 14, 2007||Oct 6, 2015||Koninklijke Philips N.V.||Electroluminescent device having a variable color point|
|US9202688||Jun 20, 2014||Dec 1, 2015||Pixelligent Technologies, Llc||Synthesis, capping and dispersion of nanocrystals|
|US9214642||Oct 25, 2013||Dec 15, 2015||Boe Technology Group Co., Ltd.||OLED device and manufacturing method thereof, display apparatus|
|US9276168||Jun 23, 2014||Mar 1, 2016||Qd Vision, Inc.||Quantum dot light enhancement substrate and lighting device including same|
|US9328432||Jun 20, 2014||May 3, 2016||Pixelligent Technologies, Llc||Synthesis, capping and dispersion of nanocrystals|
|US9349975||Mar 12, 2009||May 24, 2016||Qd Vision, Inc.||Composite including nanoparticles, methods, and products including a composite|
|US9359689||Oct 26, 2012||Jun 7, 2016||Pixelligent Technologies, Llc||Synthesis, capping and dispersion of nanocrystals|
|US20020135297 *||Feb 19, 2002||Sep 26, 2002||Seiko Epson Corporation||EL element, EL display, and electronic apparatus|
|US20030003300 *||Mar 28, 2002||Jan 2, 2003||Korgel Brian A.||Light-emitting nanoparticles and method of making same|
|US20030015955 *||Feb 14, 2002||Jan 23, 2003||Masatoshi Shiiki||Light source and display using the same|
|US20030032192 *||Sep 7, 2001||Feb 13, 2003||Stephan Haubold||Synthesis of nanoparticles|
|US20030034486 *||Mar 28, 2002||Feb 20, 2003||Korgel Brian A.||Applications of light-emitting nanoparticles|
|US20030066998 *||Aug 2, 2002||Apr 10, 2003||Lee Howard Wing Hoon||Quantum dots of Group IV semiconductor materials|
|US20030111955 *||Dec 17, 2001||Jun 19, 2003||General Electric Company||Light-emitting device with organic electroluminescent material and photoluminescent materials|
|US20030209972 *||May 10, 2002||Nov 13, 2003||Holmes Russell James Delmar||Organic light emitting devices based on the formation of an electron-hole plasma|
|US20030222578 *||May 28, 2002||Dec 4, 2003||Eastman Kodak Company||OLED area illumination light source having flexible substrate on a support|
|US20030227255 *||Jun 10, 2002||Dec 11, 2003||Institute Of Materials Research And Engineering||Patterning of electrodes in oled devices|
|US20030230980 *||Jun 18, 2002||Dec 18, 2003||Forrest Stephen R||Very low voltage, high efficiency phosphorescent oled in a p-i-n structure|
|US20040032205 *||Aug 16, 2002||Feb 19, 2004||Michael Hack||Organic light emitting devices for illumination|
|US20040036130 *||Aug 2, 2002||Feb 26, 2004||Lee Howard Wing Hoon||Methods of forming quantum dots of group iv semiconductor materials|
|US20040124504 *||Sep 24, 2003||Jul 1, 2004||Che-Hsiung Hsu||Electrically conducting organic polymer/nanoparticle composites and methods for use thereof|
|US20040126072 *||Aug 2, 2002||Jul 1, 2004||Hoon Lee Howard Wing||Optical devices with engineered nonlinear nanocomposite materials|
|US20040126582 *||Aug 21, 2003||Jul 1, 2004||Nano-Proprietary, Inc.||Silicon nanoparticles embedded in polymer matrix|
|US20040140758 *||Jan 17, 2003||Jul 22, 2004||Eastman Kodak Company||Organic light emitting device (OLED) display with improved light emission using a metallic anode|
|US20040161632 *||Feb 18, 2004||Aug 19, 2004||Lg Electronics Inc.||Organic electroluminescent device and method for fabricating the same|
|US20040189193 *||Mar 25, 2004||Sep 30, 2004||Yazaki Corporation||Dial plate, a method for producing the dial plate, and an apparatus for producing the dial plate|
|US20040217696 *||Oct 31, 2003||Nov 4, 2004||Kim Young Chul||Polymeric electroluminescent device using an emitting layer of nanocomposites|
|US20040245912 *||Apr 1, 2004||Dec 9, 2004||Innovalight||Phosphor materials and illumination devices made therefrom|
|US20040252488 *||Apr 1, 2004||Dec 16, 2004||Innovalight||Light-emitting ceiling tile|
|US20040262583 *||Jul 16, 2004||Dec 30, 2004||Lee Howard Wing Hoon||Quantum dots of group IV semiconductor materials|
|US20050001532 *||Jul 2, 2003||Jan 6, 2005||Srivastava Alok Mani||Green phosphor for general illumination applications|
|US20050017260 *||Jul 16, 2004||Jan 27, 2005||Lee Howard Wing Hoon||Quantum dots of group IV semiconductor materials|
|US20050029927 *||Aug 7, 2003||Feb 10, 2005||Setlur Anant Achyut||Deep red phosphor for general illumination applications|
|US20050062406 *||Mar 26, 2004||Mar 24, 2005||Toshihiro Kinoshita||Organic electroluminescent device and manufacturing method thereof|
|US20050081907 *||Oct 20, 2003||Apr 21, 2005||Lewis Larry N.||Electro-active device having metal-containing layer|
|US20050082523 *||Jun 25, 2004||Apr 21, 2005||Blanchet-Fincher Graciela B.||Methods for forming patterns on a filled dielectric material on substrates|
|US20050181212 *||Feb 17, 2004||Aug 18, 2005||General Electric Company||Composite articles having diffusion barriers and devices incorporating the same|
|US20050202348 *||Mar 11, 2005||Sep 15, 2005||Canon Kabushiki Kaisha||Substrate, conductive substrate, fine structure substrate, organic field effect transistor and manufacturing method thereof|
|US20050221122 *||Mar 28, 2005||Oct 6, 2005||Seiko Epson Corporation||Organic electroluminescence device, manufacturing method thereof and electronic equipment|
|US20050242346 *||Jul 8, 2005||Nov 3, 2005||Forrest Stephen R||Very low voltage, high efficiency pholed in a p-i-n structure|
|US20050266697 *||Oct 7, 2004||Dec 1, 2005||The University Of Texas System, Board Of Regents||Light-emitting nanoparticles and method of making same|
|US20050267345 *||May 5, 2005||Dec 1, 2005||The University Of Texas System, Board Of Regents||Applications of light-emitting nanoparticles|
|US20050281948 *||Jun 17, 2004||Dec 22, 2005||Eastman Kodak Company||Vaporizing temperature sensitive materials|
|US20060028129 *||Mar 29, 2005||Feb 9, 2006||Takahisa Sakakibara||Organic electroluminescent device|
|US20060034065 *||Aug 10, 2005||Feb 16, 2006||Innovalight, Inc.||Light strips for lighting and backlighting applications|
|US20060040135 *||Aug 5, 2005||Feb 23, 2006||Seiko Epson Corporation||Electroluminescent device and method of fabricating the same, and electronic apparatus|
|US20060094859 *||Feb 22, 2005||May 4, 2006||Marrocco Matthew L Iii||Class of bridged biphenylene polymers|
|US20060151800 *||Jun 10, 2004||Jul 13, 2006||Keong Chan M||Surface mountable light emitting device|
|US20060158103 *||Dec 5, 2005||Jul 20, 2006||Idemitsu Kosan Co., Ltd.||Organic electroluminescent display|
|US20060169986 *||Feb 2, 2005||Aug 3, 2006||Gelcore, Llc||Red emitting phosphor materials for use in LED and LCD applications|
|US20060169998 *||Feb 28, 2006||Aug 3, 2006||Gelcore, Llc||Red line emitting phosphor materials for use in LED applications|
|US20060170336 *||Jul 1, 2004||Aug 3, 2006||Masayuki Ono||Light emitting element and display device|
|US20060208270 *||Mar 17, 2005||Sep 21, 2006||Gelcore, Llc||Borate phosphor materials for use in lighting applications|
|US20060271132 *||May 24, 2004||Nov 30, 2006||Ledeep Llc||Skin tanning and light therapy system and method|
|US20070029906 *||Oct 12, 2006||Feb 8, 2007||Michael Hack||Organic light emitting devices for illumination|
|US20070114562 *||Nov 22, 2005||May 24, 2007||Gelcore, Llc||Red and yellow phosphor-converted LEDs for signal applications|
|US20070138460 *||Sep 25, 2006||Jun 21, 2007||Samsung Electronics Co., Ltd.||Light emitting device with three-dimensional structure and fabrication method thereof|
|US20070205712 *||Feb 13, 2007||Sep 6, 2007||Lumination, Llc||Red line emitting phosphors for use in LED applications|
|US20070210323 *||Nov 19, 2004||Sep 13, 2007||Cambridge Display Technology Limited||Optical Device|
|US20070241657 *||Jun 4, 2007||Oct 18, 2007||Lumination, Llc||White light apparatus with enhanced color contrast|
|US20070276455 *||Mar 9, 2005||Nov 29, 2007||Ledeep Llc||Phototherapy Systems And Methods|
|US20080049442 *||Sep 19, 2006||Feb 28, 2008||Choo Dae-Ho||Light emitting device and display apparatus using the same|
|US20080084159 *||Dec 21, 2005||Apr 10, 2008||Christophe Fery||Organic Double-Sided Light-Emitting Diode with a Light Extraction Dielectric Layer|
|US20080096135 *||Jul 5, 2007||Apr 24, 2008||Blanchet-Fincher Graciela B||Methods for forming patterns of a filled dielectric material on substrates|
|US20080105370 *||Dec 14, 2005||May 8, 2008||Marc Schaepkens||Composite articles having diffusion barriers and devices incorporating the same|
|US20080135809 *||Dec 28, 2007||Jun 12, 2008||Che-Hsiung Hsu||Electrically conducting organic polymer/nanoparticle composites and method for use thereof|
|US20080152938 *||Aug 21, 2007||Jun 26, 2008||Maxim Kelman||Group iv nanoparticles and films thereof|
|US20080169753 *||Jan 11, 2007||Jul 17, 2008||Motorola, Inc.||Light emissive printed article printed with quantum dot ink|
|US20080210909 *||Dec 20, 2007||Sep 4, 2008||Che-Hsiung Hsu||Compositions of polyaniline made with perfuoropolymeric acid which are heat-enhanced and electronic devices made therewith|
|US20080213594 *||Dec 20, 2007||Sep 4, 2008||Che-Hsiung Hsu||Laser (230nm) ablatable compositions of electrically conducting polymers made with a perfluoropolymeric acid applications thereof|
|US20080237470 *||Mar 26, 2007||Oct 2, 2008||General Electric Company||Polymeric composite scintillators and method for making same|
|US20080241040 *||Mar 26, 2007||Oct 2, 2008||General Electric Company||Nano-scale metal halide scintillation materials and methods for making same|
|US20080248314 *||May 13, 2008||Oct 9, 2008||Che-Hsiung Hsu||Water dispersible polythiophenes made with polymeric acid colloids|
|US20080265749 *||Sep 25, 2006||Oct 30, 2008||Koninklijke Philips Electronics, N.V.||Phosphor-Converted Electroluminescent Device with Absorbing Filter|
|US20080296536 *||Jul 29, 2008||Dec 4, 2008||Che-Hsiung Hsu||Water dispersible polythiophenes made with polymeric acid colloids|
|US20090014423 *||Jul 10, 2007||Jan 15, 2009||Xuegeng Li||Concentric flow-through plasma reactor and methods therefor|
|US20090020775 *||Jul 16, 2008||Jan 22, 2009||Lumination Llc||RED LINE EMITTING COMPLEX FLUORIDE PHOSPHORS ACTIVATED WITH Mn4+|
|US20090044661 *||May 1, 2008||Feb 19, 2009||Xuegeng Li||Methods and apparatus for the production of group iv nanoparticles in a flow-through plasma reactor|
|US20090053878 *||Oct 19, 2007||Feb 26, 2009||Maxim Kelman||Method for fabrication of semiconductor thin films using flash lamp processing|
|US20090059554 *||Aug 28, 2007||Mar 5, 2009||Motorola, Inc.||Apparatus for selectively backlighting a material|
|US20090072201 *||Nov 21, 2008||Mar 19, 2009||E. I. Du Pont De Nemours And Company||Water dispersible polyanilines made with polymeric acid colloids for electronics applications|
|US20090074649 *||Jun 4, 2008||Mar 19, 2009||Korgel Brian A||Light-emitting nanoparticles and methods of making same|
|US20090152497 *||Dec 12, 2007||Jun 18, 2009||General Electric Company||Persistent phosphor|
|US20090152567 *||Sep 5, 2008||Jun 18, 2009||Mark Comerford||Article including semiconductor nanocrystals|
|US20090162011 *||Sep 12, 2008||Jun 25, 2009||Seth Coe-Sullivan||Compositions, optical component, system including an optical component, devices, and other products|
|US20090215209 *||Oct 7, 2008||Aug 27, 2009||Anc Maria J||Methods of depositing material, methods of making a device, and systems and articles for use in depositing material|
|US20090255222 *||Apr 15, 2009||Oct 15, 2009||Raul Cortez||Methods and apparatus for the in situ collection of nucleated particles|
|US20090278141 *||Nov 24, 2008||Nov 12, 2009||Seth Coe-Sullivan||Light-emitting devices and displays with improved performance|
|US20090283742 *||Dec 19, 2008||Nov 19, 2009||Seth Coe-Sullivan||Methods and articles including nanomaterial|
|US20090283743 *||Nov 19, 2009||Seth Coe-Sullivan||Composite including nanoparticles, methods, and products including a composite|
|US20090283778 *||Nov 19, 2009||Seth Coe-Sullivan||Electroluminescent display useful for displaying a predetermined pattern|
|US20100026176 *||Jul 31, 2009||Feb 4, 2010||Jan Blochwitz-Nomith||Transparent, Thermally Stable Light-Emitting Component Having Organic Layers|
|US20100033091 *||Feb 11, 2010||Glory Science Co., Ltd.||Light emitting unit and method of manufacturing the light emitting unit|
|US20100045175 *||Feb 25, 2010||Plexotronics, Inc.||Organic light emitting diode lighting devices|
|US20100045189 *||Feb 25, 2010||Plextronics, Inc.||Organic light emitting diode lighting systems|
|US20100046210 *||Feb 25, 2010||Plextronics, Inc.||Organic light emitting diode products|
|US20100051901 *||Mar 4, 2010||Kazlas Peter T||Light emitting devices and displays with improved performance|
|US20100076527 *||Mar 25, 2010||Plextronics, Inc.||User configurable mosaic light emitting apparatus|
|US20100090590 *||Feb 15, 2008||Apr 15, 2010||Mitsubishi Chemical Corporation||Organic electroluminescence device and method of producing organic device|
|US20100265307 *||Oct 21, 2010||Linton John R||Compositions and methods including depositing nanomaterial|
|US20100327309 *||Dec 7, 2007||Dec 30, 2010||Koninklijke Philips Electronics N.V.||Voltage-operated layered arrangement|
|US20110024685 *||Jan 21, 2010||Feb 3, 2011||General Electric Company||Nano-scale metal oxyhalide and oxysulfide scintillation materials and methods for making same|
|US20110155966 *||Jun 30, 2011||E.I. Du Pont De Nemours And Company||Electrically conducting organic polymer/nanoparticle composites and methods for use thereof|
|US20110168952 *||Jul 14, 2011||E. I. Du Pont De Nemours And Company||High work-function and high conductivity compositions of electrically conducting polymers|
|US20110175029 *||Jul 21, 2011||General Electric Company||Persistent phosphor|
|US20120080668 *||Sep 26, 2011||Apr 5, 2012||Seiko Epson Corporation||Organic el lighting device and method of manufacturing the same|
|US20120313124 *||Jun 7, 2011||Dec 13, 2012||David Clatterbuck||Galium-substituted yttrium aluminum garnet phosphor and light emitting devices including the same|
|US20140042928 *||Aug 6, 2013||Feb 13, 2014||Canon Kabushiki Kaisha||Light-emitting device|
|US20140264987 *||Mar 15, 2013||Sep 18, 2014||Nitto Denko Corporation||Method of manufacturing phosphor translucent ceramics and light emitting devices|
|USRE44853||Apr 18, 2012||Apr 22, 2014||E I Du Pont De Nemours And Company||Buffer compositions|
|CN1817064B||Jul 1, 2004||Dec 1, 2010||松下电器产业株式会社||Light emitting element and display device|
|CN100442570C||Jul 9, 2004||Dec 10, 2008||三星Sdi株式会社||Electroluminescent device using metal nano-particles|
|CN100477874C||Aug 18, 2005||Apr 8, 2009||精工爱普生株式会社||Electroluminescent device and method of fabricating the same, and electronic apparatus|
|CN100530741C||Feb 19, 2004||Aug 19, 2009||乐金显示有限公司||Organic electroluminescent device and method for fabricating the same|
|CN101507355B||Aug 14, 2007||Nov 17, 2010||皇家飞利浦电子股份有限公司||Electroluminescent device having a variable color point|
|CN102394274B *||May 19, 2006||Jul 1, 2015||乐金显示有限公司||Display devices with light absorbing metal nonoparticle layers|
|CN103325952A *||Jul 4, 2013||Sep 25, 2013||京东方科技集团股份有限公司||Organic light emitting diode (OLED) device and manufacturing method and display device thereof|
|CN103717705A *||May 31, 2012||Apr 9, 2014||科锐||Gallium-substituted yttrium aluminum garnet phosphor and light emitting devices including the same|
|CN103811670A *||Feb 20, 2013||May 21, 2014||周卓辉||Candlelight-like light organic light-emitting device|
|CN103811670B *||Feb 20, 2013||Jan 20, 2016||周卓辉||类烛光有机发光二极管|
|DE102007016401A1||Apr 3, 2007||Oct 9, 2008||Saint-Gobain Sekurit Deutschland Gmbh & Co. Kg||Elektrolumineszierendes Schichtelement|
|DE202007019199U1||Apr 3, 2007||Feb 10, 2011||Saint-Gobain Sekurit Deutschland Gmbh & Co. Kg||Elektrolumineszierendes Schichtelement|
|EP2112702A1 *||Feb 15, 2008||Oct 28, 2009||Mitsubishi Chemical Corporation||Organic field emitting element and method for manufacturing organic device|
|WO2004001796A2 *||May 6, 2003||Dec 31, 2003||The Trustees Of Princeton University||Organic light emitting devices based on the formation of an electron-hole plasma|
|WO2004001796A3 *||May 6, 2003||Jul 15, 2004||Univ Princeton||Organic light emitting devices based on the formation of an electron-hole plasma|
|WO2004017678A3 *||Aug 18, 2003||Oct 6, 2005||Universal Display Corp||Organic light emitting devices for illumination|
|WO2004019418A1 *||Aug 22, 2003||Mar 4, 2004||Nano-Proprietary, Inc.||Silicon nanoparticles embedded in polymer matrix|
|WO2004075604A2 *||Feb 19, 2004||Sep 2, 2004||Lg Electronics Inc.||Organic electroluminescent device and method for fabricating the same|
|WO2004075604A3 *||Feb 19, 2004||Nov 11, 2004||Lg Electronics Inc||Organic electroluminescent device and method for fabricating the same|
|WO2007138298A1 *||May 25, 2007||Dec 6, 2007||Cambridge Enterprise Limited||Enhancing performance in ink-jet printed organic semiconductors|
|WO2008020396A1||Aug 14, 2007||Feb 21, 2008||Philips Intellectual Property & Standards Gmbh||Electroluminescent device having a variable color point|
|WO2010022104A2 *||Aug 18, 2009||Feb 25, 2010||Plextronics, Inc.||Organic light emitting diode lighting systems|
|WO2010022104A3 *||Aug 18, 2009||Jun 24, 2010||Plextronics, Inc.||Organic light emitting diode lighting systems|
|WO2012170266A1 *||May 31, 2012||Dec 13, 2012||Cree, Inc.||Gallium-substituted yttrium aluminum garnet phosphor and light emitting devices including the same|
|WO2015000242A1 *||Oct 25, 2013||Jan 8, 2015||Boe Technology Group Co., Ltd.||Oled device, manufacturing method thereof and display device|
|U.S. Classification||257/184, 313/501, 257/98, 313/506, 313/507, 257/89, 257/E25.008, 257/103, 313/503, 257/40|
|International Classification||H01L27/32, H01L51/50, H01L25/04|
|Cooperative Classification||B82Y30/00, H01L51/5048, H01L2251/5369, H01L2251/5361, H01L25/046, H01L51/5088, H01L2924/0002, B82Y20/00, H01L51/5092, H01L27/3211, H01L51/5036|
|European Classification||B82Y30/00, B82Y20/00, H01L51/50E8|
|Nov 16, 2000||AS||Assignment|
Owner name: GENERAL ELECTRIC COMPANY, NEW YORK
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Owner name: BOE TECHNOLOGY GROUP CO., LTD., CHINA
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